Preparation of metals and metal alloys



United States Patent 3,458,306 PREPARATION OF METALS AND METAL ALLOYSRobert H. Lindquist, Berkeley, Calif., assignor to Chevron ResearchCompany, San Francisco, 'Calif., a corporation of Delaware No Drawing.Filed Sept. 27, 1966, Ser. No. 582,238 Int. Cl. B22f 1/00, 9/00 US. Cl.75-.5 2 Claims ABSTRACT OF THE DISCLOSURE Process for preparingdispersion-hardened metals and metal alloys, comprising forming asolution comprising metal chloride precursors of the continuous anddispersed phases of the final product, adding an epoxy compound to saidsolutions whereby a gel comprising metal hydroxides is formed,converting said metal hydroxides to oxides, and reducing the oxideprecursors of the continuous phase of the final product, and products soprepared.

INTRODUCTION Various methods are known for producing metals and metalalloys in which particles of a refractory oxide of a different metal areincorporated to improve various characteristics of the metals and metalalloys. The incorporation of the refractory oxide particles is known asdispersion strengthening, the metal or metal alloy is referred to as thecontinuous phase, and the refractory oxide particles are referred to asthe dispersed phase or filler.

The dispersed phase generally is incorporated in the continuous phaseby: (a) selecting as the dispersed phase particles of a metal oxidematerial that has a high free energy of formation, AT, and thereforethat is resistant 3,458,306 Patented July 29, 1969 (A) articles andpapers:

(1) A Theory of Dispersion Strengthening, paper by F. V. Lenel and G. S.Ansell, presented at 1960 International Powder Metallurgy Conference,pp. 267-307.

(2) New Design Data on TD Nickel, Robert E. Stuart, Materials in DesignEngineering, August 1963, pp. 81-85.

(3) Dispersion Strengthening Models, G. S. Ansell and J. S. Hirschhorn,ACTA Metallurgica, vol. 13, 1965, pp. 573-576.

(4) Creep of Thoriated Nickel Above and Below 0.5 T B. A. Wilcox and A.H. Clauer, Transactions of the Metallurgical Society of AIME, vol. 236,April 1966, pp. 570-580.

(5) The Structure of Nickel Electrodeposited With Alumina Particles, E.Gillam, K. M. Movie and M. Phillips, Journal of the Institute of Metals,vol. 94, pp. 228-229.

(B) US. patents:

(1) Alexander et al. 2,972,529 (2) Alexander et al. 3,019,103 (3) Grantet al. 3,069,759 (4) Grant et al. 3,176,386

DISADVANTAGES OF VARIOUS PRIOR ART M E T H O D S OF PRODUCING DISPERSIONSTRENGTHENING METALS A N D METAL ALLOYS Prior art methods of producingdispersion strengthened metals and metal alloys involve numerousdisadvantages.

In a typical prior art method of producing thoria dispersed nickel,particles of thoria are mixed in an aqueous solution of nickel nitrate,and the nickel nitrate is precipitated with sodium hydroxide duringvigorous agitation, thus depositing nickel hydroxide around the thoriaparticles. The resulting precipitate must be filtered and to reductionto the metal in hydrogen, (b) forming around the dispersed phase acontinuous phase of one or more metal compounds easily reducible tometal in hydrogen, (c) subjecting the resulting mass to a reducingtreatment in hydrogen, whereby'the continuous phase is converted tometal form without concurrent reduction to the metal of the dispersedoxide phase, and (d) pressing the resulting powdery mass under highpressure into a dense coherent compact, which can be further worked, forexample rolled, extruded or machined.

Various theories and models, sometimes conflicting, have been proposedto predict and/or explain the improvement in strength and othercharacteristics of metals and alloys that results from the presencetherein of a dispersed phase of refractory oxide particles. It is not apresent purpose to present any such theories or models, because whateverthe correct theory or model may be there is no dispute that thedispersed phase results in improved characteristics of metals and metalalloys, particularly improved strength characteristics, especially inhigh temperature service. Prior art theories and models, and methods ofpreparation of dispersion strengthened metals and metal alloys, are wellset forth in many publications, including the following articles andpapers and US. patents:

washed to remove sodium nitrate. The precipitate is then dried toconvert the nickel hydroxide to nickel oxide. The nickel oxide is thenreduced to nickel metal. The nickel metal is in the form of a powdercontaining dispersed thoria particles. The powder may be fabricated, asby hot pressing, extrusion, etc. In such a process these disadvantagesexist:

(a) No control exists over the size of the dispersed oxide particlesduring conduct of the process.

(b) Particle size must be selected in advance, from a range of sizesthat is limited to sizes producible by available technology.

(c) Selective precipitation and selective crystallization, particularlyin the case of metal alloy preparation, are caused by nonhomogeneity oforiginal mixture, and are serious problems that can be controlled onlyin part by vigorous agitation. Final product quality is drasticallyaffected by minor deviations from uniformity of dispersion of the oxideparticles in the original mixture.

(d) Soluble salts such as sodium nitrate must be essentially completelyremoved by washing, because such contaminants adversely affect finalproduct quality. It is known that such complete removal is extremelydifficult.

OBJECTS In view of the foregoing, it is an object of the presentinvention to provide a process for producing metals and metal alloysfrom metal salts, and particularly for producing metals and metal alloysin a continuous phase containing a dispersed phase of refractory metaloxide particles, that avoids the aforesaid disadvantages.

It is a further object of the present invention to provide, in such aprocess for producing dispersion strengthened metals and metal alloys,means for controlling,

during conduct of the process, particle size of the continuous phasemetal or alloy, as well as dispersed oxide particle size.

STATEMENT OF INVENTION In accordance with a first embodiment of thepresent invention there is provided a process for producing metals andmetal alloys which comprises:

(A) Forming a solution comprising (a) At least one metal chlorideselected from the chlorides of metals which in the oxide form arereducible to the metal form in hydrogen at a temperature in the range600 to 1800 F,

(b) At least one metal chloride selected from the chlorides of metalsthe oxides of which are not reducible in hydrogen at a temperature inthe range 600 to 1800 F., and

(c) A lower alkanol;

(B) Adding to said solution an epoxy compound, whereby the components ofsaid solution and said epoxy compound react to form a mixture comprisingchlorohydrins and a gel containing at least one metal hydroxide;

(C) Separating said gel from said chlorohydrins;

(D) Converting said metal hydroxide in said gel to a metal oxide;

(E) Reducing said metal oxide to metal, and

(F) Compacting said metal to a density at least 90% of the theoreticaldensity.

In accordance with a second embodiment of the present invention there isprovided a process for preparing a material comprising a continuousphase selected from metals and metal alloys surrounding a dispersedphase of re fractory metal oxide particles, which comprises:

(A) Forming a solution comprising (a) At least one metal chlorideselected from the chlorides of metals which in the oxide form arereducible to the metal form in hydrogen at a temperature in the range600 to 1800 F., the metal cation of said metal chloride being present insaid solution in an amount of at least 70 weight percent of the totalmetal cations in said solution,

(b) At least one metal chloride selected from the chlorides of metalsthe oxides of which are not reducible in hydrogen at a temperature inthe range 600 to 1800 F., the metal cation of said metal chloride beingpresent in said solution in an amount of less than 30 weight percent ofthe total metal cations in said solution, and

(c) A lower alkanol;

(B) Adding to said solution an epoxy compound selected from the groupconsisting of lower alkylene oxides and epichlorohydrins, whereby a gelcomprising metal hydroxides is formed;

(C) Converting said metal hydroxides to oxides, including metal oxidesreducible in hydrogen at 600 to 1800 F., and metal oxides not soreducible;

(D) Subjecting the resulting metal oxide-containing material to areducing treatment at a temperature in the range 600 to 1800 F.

The metals which in the oxide form are reducible to the metal form inhydrogen at a temperature in the range 600 to 1800 F. include Ni, Co,Fe, Cu, Cd, Tl, Ge, Sn, Pb, Bi, Mo, W, Re and In.

The metals the oxides of which are not reducible in hydrogen at atemperature in the range 600 to 1800 F. include Y, Ca, La, Be, Th, Mg,U, Hf, Ce, Al, Zr, Ba, Ti, Si, Ta, V, Nb and Cr.

In accordance with a third, and preferred, embodiment of the presentinvention there is provided, in a process for producing a compositioncomprising a continuous phase comprising a material selected from thegroup consisting of iron, cobalt, nickel and alloys of at least two ofthese metals with each other, said composition further comprising adispersed phase comprising particles of a refractory metal oxide, theimprovement which comprises:

(A) Forming a solution comprising (a) At least one metal chlorideselected from the group consisting of iron chloride, cobalt chloride andnickel chloride, the metal cation of said metal chloride being presentin said solution in an amount of at least 70 weight percent of the totalmetal cations in said solution, and

(b) At least one metal chloride selected from the chlorides of Y, Ca,La, Be, Th, Mg, U, Hf, Ce, Al, Zr, Ba, Ti, Si, Ta, V, Nb and Cr, themetal cation of said metal chloride being present in said solution in anamount of less than 30 weight percent of the total metal cations in saidsolution, and

(c) A lower alkanol;

(B) Adding to said solution an epoxy compound selected from the groupconsisting of lower alkylene oxides and epichlorohydrins, whereby thecomponents of said solution and said epoxy compounds react to form amixture comprising chlorohydrins and a gel containing at least one metalhydroxide;

(C) Subjecting said gel to a calcination treatment, whereby said metalhydroxides are converted to metal oxides;

(D) Subjecting the resulting metal oxide-containing material to areducing treatment, whereby all iron, cobalt and nickel oxides presentare reduced to the corresponding metals, without reduction of at leastone other oxide present.

The epoxy compound used in the process of the present invention may beany epoxy compound that will react at a reasonable rate with the anionof the metal salt or metal salts present. The epoxy compound preferablyis a lower alkylene oxide or an epichlorhydrin. Said lower alkyleneoxide may be, for example, ethylene oxide, propylene oxide or butyleneoxide.

The lower alkanol used in the process of the present invention may beany lower alkanol, including methanol, ethanol, l-propanol, 2-propanol,l-butanol, Z-butanol, 2- methyl-2-propanol, and Z-methyl-l-propanol.

In the process of the present invention a mixture, comprisingchlorohydrins and a metal hydroxide-containing gel, results from theaddition of an epoxy compound to the starting solution. Upon drying,this mixture conveniently releases the chlorohydrins, which vaporize oileasily. Accordingly, no washing or other contaminant removal proceduresare required.

EXAMPLES Example 1 A solution of the following composition was prepared:NiCl -6H O g 1270 AlCl -6H O g 6.4 MeOH litres 2 A 1500 cc. quantity ofpropylene oxide was added to the solution at room temperature. In 40minutes the resulting mixture had set up into a gel.

Approximately weight percent of said gel was subjected to a calcinationtreatment in an oxygen-containing atmosphere, as follows:

(a) 4 hours in air at 800 F., then (b) 4 hours in 0 at 1000 F.

The material resulting from the calcination treatment was a crumbly orpowdery mass. It was subjected to a reducing treatment in an ebullatingbed reactor, to reduce the nickel oxide portion thereof to nickel metal,as follows:

(a) 1 hour in H at 600 F., then (b) 2 hours in H at 800 F., then (c) 2hours in H at 1000 F., then (d) 2 hours in H at 1450 F.

The ebullating bed reactor consisted of an upright quartz tubecontaining at the base a fritted quartz disc through which the hydrogenpassed and caused the powder to 5 6 bubble up or ebullate in the sapceabove the disc, thereby Example 3 preventing appreciable powderSll'ltCIlIlg during the re- A solution of the following composition wasprepared: duction reaction, wh1ch would otherwise occur, partic- Nicl g1200 ularly at temperatures above about 1000 F. M6011 2 a t 1875 Thematerial resulting from the reducing treatment was "T" a powder, whichwas found to weight 320 grams, and to An 11.00 quantlty of propyleneoxlde. was .added to consist essentially of 98 weight percent nickelmetal and the .Solutlon at m temperafure' The resultmg mlxture Set 2Weight percent AI2O3 up into a gel, which was dried 48 hours at roomtemper- A portion of the nickel-A1 0 powder was hot pressed g 72 glowsat i i to a cylindrically shaped compact having a diameter of pproxlmatey 95 i percent of Said. gel was 11/2 inches and a thickness of 14 inch,in a graphite die ected to the same calcination treatment as inExample 1. under a low pressure of hydrogen for 1/2 hour at a Thematerial resulting from the calcination treatment was Perature of 11000C. and a pressure of 3500 psig The sub ected to the same reducingtreatment as in Example 1. resulting cylindrical compact was rolled tolower its thick- Thedmaterfil fi frcm the pi treatment was ness 10%, andwas then annealed in hydrogen at 1100 C. 15 W .1 2 to i 300 grams and toThe so annealed compact could be cold rolled to a t-hickconsist es.sennay 0 i 6 meta ness of 0.050 inch without further annealing, and this Aporno of the mckel metal powder f hot Pressed was done. From theresulting 0.050 inch thick material two rolled annealed fufther rolledand.machmed to produce elongated tensile strength specimens weremachined. tWQ .elongated tenslle Strengih spFclmens an exactly Said twotensile strength specimens were tested for cordlpg to the prpceduremelted i Example tensile strength at elevated temperature, in a 10,000Siiud two tenslle strength Speclmens were tested for pound capacitytensile test machine, at a cross head speed ienslle Strength at elevate?temperature exactly accord of 0.020 inch per minute, after the specimenshad been mg to the procedur? used.m Example heated to a stabletemperature of 2200 F. in a wire The results of sald tenslle str-engthtests were: wound furnace for about 5 hours. Tension was applied FirstSecond by the machine pull rods to each specimen via dispersion specimenspecimen lilardened nickel pins inserted in holes near each end ofpercent elongation of 1 inch gage length of 4 6 t e specimen. R

The results of said tensile strength tests were: Ummate tenslle strength480 2'500 Example 4 ,31 ,35,322 A solution of the following compositionwas prepared: Percent elongation of 1 inch gage length of N1cl2'6H2O2540 specimen 1.0 ThCL; g 10.0

Ultimate tensile strength, p.s.1 5, 270 4, 000 o litres 4 E 1 2 A 1060ml. quantity of propylene oxide was added to the xampe solution at roomtemperature. The resulting mixture set A solution of the followingcomposition was prepared: up into a gel within 1 hour.

Approximately 95 weight percent of said gel was sub- 2 jected to acalcination treatment in air for 6 hour at MeoeH 2 g g 1100 F. Thematerial resulting from the calcination treatment was subjected to thesame reducing treatment A 1500 cc. quantity of proylene oxide was addedto the as in Example 1. solution at room temperature. In 40 minutes theresulting The material resulting from the reducing treatment mixture hadset up into a gel. was a powder, which was found to weigh 600 grams, and

Approximately 95 weight percent of said gel was subto consistessentially of 98 weight percent nickel metal jected to the samecalcination treatment as in Example and 2 weight percent ThO 1. Thematerial resulting from the calcination treatment The ThO in saidmaterial was determined by electron was subjected to the same reducingtreatment as in Exmlcroscope examination to be in the form of particlesample 1, having an averaye diameter of 200 angstroms.

The material resulting from the reducing treatment was A portion of thenickel-Th0 powder was hot pressed, a powder, which was found to weight320 grams, and to rolled, annealed, further rolled, and machined toproduce consist essentially of 96 weight percent nickel metal and anelongated tensile strength specimen, all exactly ac- 4 weight percent A10 cord ng to the procedure recited in Example 1.

A portion of the nickel-A1 0 powder was hot pressed, Said tensllestrength specimen was tested for tensile rolled, annealed, furtherrolled, and machined to produce Strength at elevated temperature,exactly according to the an elongated tensile strength specimen, allexactly accord- Procedure used 111 E p ing to the procedure e ited inExample 1, The results of sald tensile strength tests were:

Said tensile strength specimen was tested for tensile P t elongation of1 i h gage length of strength at elevated temperature, exactly accordingto the specimen 2.5 procedure used in Example 1. Ultimate tensilestrength, p.s.i 3800 The results of said tensile strength test were:Example 5 Percent elongation of 1 inch gage length of In a mannersimilar to that set forth in Examples 14,

specimen 1.6 these further metal-dispersed oxide specimens were pre-Ultimate tensile strength, psi. 2510 pared:

Weight percent Specimen No. 5 6 7 8 9 10 11 12 13 14 Component:

Ni metal Example 6 In a manner similar to that set forth in Examples 14,these further metal alloy-dispersed oxide compositions were prepared:

Weight percent Specimen N0.

Component:

Fe metal PROCESS CONDITIONS AND PARTICLE SIZES The gel formation step ofthe present process may be conducted at ambient to slightly elevatedtemperatures.

The desired particle size for the dispersed refractory metal oxidecomponent in the final product, when dispersion hardened metals or metalalloys are produced by the present process, is 0.005 to 0.1 micron indiameter. Contrary to prior art processes, this particle size varies asa function of process conditions, thereby providing great flexibility tothe process. The size of the dispersed refractory metal oxide particlesis a function of the temperature during the calcination step, and thelength of time the step is conducted. The temperature is in the generalrange 800 to 2400 F., with smaller particles resulting from the use oflower temperatures and shorter periods. Temperatures should be chosenwith regard to the particle size desired and the melting points of thematerials used. When operating within the ranges set forth herein forproportions of ingredients, calcination temperatures, etc., thedispersed oxide particles in the final product will be extremelyuniformly dispersed, and will have an interparticle spacing of 0.01 to1.0 micron.

The grain size of the metal and metal alloy continuous phases of theproducts produced by the process of the, present invention is a functionof the temperature during the reduction step, and the length of time thestep is conducted. The temperature is in the general range 600 to 1800F., with smaller grain sizes resulting from the use of lowertemperatures and shorter periods. A preferred temperature-timecombination is 600 to 1600 F. for not substantially longer thannecessary for reduction reactions to be completed. A gradual increase intemperature from a temperature in the range of about 600 to 800 F. to ahigher temperature will provide these advantages: (a) much of thereduction will occur at lower temperatures, which contribute to afine-grained final product; (b) the subsequent higher temperatures willshorten the time necessary for completion of the reduction reactions,and a minimal time at a given temperature also contributes to afine-grained final product; and (c) the length of time the reductionstep is conducted at temperatures above 1000 R, where care must be takento avoid powder sintering, can be minimized.

Exceptionally fine-grained metal and metal alloy continuous phases canbe obtained in the products produced by the process of the presentinvention. Further, it is well known that a grain growth phenomenonoccurs in conventional dispersion hardened metal and metal alloy shapedmaterials during stressing of the materials, particularly at elevatedtemperatures. Dispersion hardened metal and metal alloy shaped materialsmade from products of the present process show a markedly reduced graingrowth, compared with the conventional materials, probably due in largepart to the excellent and uniform dispersion of the dispersed oxidephase. Grain diameters tional dispersion hardened shapes of the samecomposition after the same tensile strength tests.

Recrystallization of conventional shaped dispersion strengthenedmaterials after extensive cold rolling, resulting in coarse grain size,is a known problem. The shaped materials made from products of thepresent process have demonstrated superior resistance to thisrecrystallization phenomenon, compared with similar prior art materials.

PROPORTIONS OF INGREDIENTS The present process will be found to be mosthighly effective for producing high quality metals and alloys when: (1)total weight of the metal chloride starting materials is 15 to 40percent, preferably 20 to 30 percent, of the weight of the loweralkanol; and (2) the mols of epoxy compound used per mol of chloride ionis 1.1 to 2.0, preferably 1.4 to 1.8.

It is highly desirable that water be present in the starting solution inthe present process, either in the form of free water or water ofhydration. Most desirably, 2 to 6 mols of water will be present per molof chloride ion.

When producing dispersion hardened metals or metal alloys, the finalproduct after the reduction step preferably will consist of to 99.5weight percent metal or metal alloy and 20 to 0.5 weight percentdispersed refractory metal oxide. Those skilled in the art upon readingthe present specification will be able to produce products of this orany desired weight ratio of metal or metal alloy to dispersed metaloxide that is obtainable by observing the requirement that the metalcation of the metal chloride precursor of the metal or metal alloy ofthe continuous phase is present in the starting solution in an amount ofat least 70 weight percent of the total metal cation present in thatsolution. If more than 30 weight percent of the metal cations in thestarting solution were metal cations of the metal chloride precursor ofthe metal oxide dispersed phase of the final product, that product wouldhave inadequate ductility compared with the products of the presentprocess.

The proportions of the various ingredients are varied within theforegoing ranges as necessary to produce the best product with theparticular ingredients used. The best product will be obtained when aclear gel is produced in the gelation step, without accompanyingprecipitation. With this guide, and with the foregoing ranges as guides,those skilled in the art may determine optimum proportions for theparticular ingredients being used.

REDUCTION STEP The temperatures used in the step of reducing the oxideof the continuous phase material have been set forth above. Thereduction step may be carried out in a stream of hydrogen, with carebeing taken to prevent problems that can be caused by localizedoverheating, leading to temperature runaways andliquid metal formation,and

also to prevent sintering of the metal oxide particles of the dispersedphase. Such problems can be prevented by use of the ebullating bedtechnique previously described and by taking care to maintaintemperatures below the sintering temperature of the metal oxideparticles. Further aids in achieving this protection include addition ofhydrogen no faster than necessary to maintaian an ebullating bed, whenan ebullating bed is used, and dilution of the hydrogen with an inertgas such as nitrogen, as descrebed in connection with the reduction stepin US. Patent 3,019,103. The extent of reduction necessary has beendiscussed previously, and in this connection the oxygen content of theproduct set forth in connection with the reduction step in US. Patent3,019,103 is applicable.

SINTERING THE REDUCED PRODUCT Although not in all events necessary,particularly in small scale operations, the reduced product may besintered as described in US. Patent 3,019,103.

COMPACTING AND WORKING THE PRODUCT The product of the present process,in the form of a powder, may be readily compacted, and the discussion inthis connection in US. Patent 3,019,103 is applicable. The powderproduct of the present process preferably is used by compacting it to adensity at least 90%, and preferably at least 95%, of the theoreticaldensity. The resulting compact preferably is thermomechanically workedand shaped into a desired material of construction.

It is well known that further working of compacted metallic powders,particularly those containing a dispersed metal oxide phase, greatlyenhances tensile strength and other desirable properties of the finalshaped products. Those skilled in the art have available a number ofcombinations of conventional steps of thermomechanical working that areapplicable to improvement of properties of compacts prepared frompowders produced by the process of the present invention. Such furtherthermomechanical working treatments would greatly increase the tensilestrengths of the materials given in the examples in the presentapplication, as well as further enhancing other properties such as creepresistance. The further thermomechanical working treatments probablyeffectively develop an optimum and complex dislocation stopping networkcomprising dispersed oxide particles, grain boundaries andsub-boundaries, and dislocation tangles.

SUMMARY OF ADVANTAGES From the foregoing it may be seen that theadvantages of the process of the present invention, over prior artprocesses for producing metals and metal alloys, particularly dispersionstrengthened metals and metal alloys, include:

(a) Control may be exercised over grain size of the continuous phasemetal or metal alloy.

(b) Control may be exercised over particle size of the dispersed phasemetal oxide.

(c) Higher quality materials, particularly metal alloys, are more easilyproduced, because allcomponents are homogeneously dispersed in theoriginal solution, and therefore in the subsequent gel.

(d) A volatile organic material-an epoxy compound-is used to cause a gelto form, rather than causing precipitation by using a metal hydroxide orother basic hydroxide that leaves an impurity that must be removed bywashing after the precipitation is completed. The undesired componentsof the epoxy compound vaporize off as chlorohydrins, leaving nocontaminant removal problem.

(e) No washing facilities are required.

(f) Metal chloride starting materials are available at low cost comparedwith many prior art starting materials.

It may also be seen that the process of the present invention producesmaterials, particularly dispersion hardened metals and metal alloys,which may be formed into shapes having at least the followingadvantages, particularly under stress at elevated temperatures:

(a) Superior resistance to creep, occurring over relatively shortperiods.

(b) Superior resistance to fatigue, occurring over relatively longperiods.

(c) hSuperior resistance to grain growth in the continuous p ase.

(d) Superior resistance to recrystallization.

I claim:

1. A process for preparing a material comprising a continuous phaseselected from metals and metal alloys surrounding a dispersed phase ofrefractory metal oxide particles, which comprises:

(A) Forming a solution comprising (a) at least one metal chlorideselected from the chlorides of metals which in the oxide form arereducible to the metal form in hydrogen at a temperature in the range600 to 1800 F., the metal cation of said metal chloride being present insaid solution in an amount of at least 70 weight percent of the totalmetal cations in said solution, and

(b) at least one metal chloride selected from the chlorides of metalsthe oxides of which are not reducible in hydrogen at a temperature inthe range 600 to 1800 F., the metal cation of said metal chloride beingpresent in said solution in an amount of less than 30 weight percent ofthe total metal cations in said solution, and

(c) a lower alkanol;

(B) Adding to said solution an epoxy compound selected from the groupconsisting of lower alkylene oxides and epichlorohydrins, whereby a gelcomprising metal hydroxides is formed;

(C) Converting said metal hydroxides to oxides, in-

cluding oxides reducible in hydrogen at 600 to 1800 F., and metal oxidesnot so reducible;

(D) Subjecting the resulting metal oxide-containing material to areducing treatment at a temperature in the range 600 to 1800 F.

2. In a process for producing a composition comprising a continuousphase comprising a material selected from the group consisting of iron,cobalt, nickel and alloys of at least two of these metals with eachother, said composition further comprising a dispersed phase comprisingparticles of a refractory metal oxide, the improvement which comprises:

(A) Forming a solution comprising (a) at least one metal chlorideselected from the group consisting of iron chloride, cobalt chloride andnickel chloride, the metal cation of said metal chloride being presentin said solution in an amount of at least 70 weight percent of the totalmetal cations in said solution, and

(b) at least one metal chloride selected from the chlorides of Y, Ca,La, Be, Th, Mg, U, Hf, Ce, Al, Zr, Ba, Ti, Si, Ta, V, Nb and Cr, themetal cation of said metal chloride being present in said solution in anamount of less than 30 weight percent of the total metal cations in saidsolution, and

(c) a lower alkanol;

(B) Adding to said solution an epoxy compound selected from the groupconsisting of lower alkylene oxides and epichlorohydrins, whereby thecomponents of said solution and said epoxy compound react to form amixture comprising chlorohydrins and a gel containing at least one metalhydroxide;

(C) Subjecting said gel to a calcination treatment, whereby said metalhydroxides are converted to metal oxides;

(D) Subjecting the resulting metal oxide-containing 1 1 r 1 2 materialto a reducing treatment, whereby all iron, 3,317,285 5/1967 Alexander etal 75.5 cobalt and nickel oxides present are reduced to 3,386,814 6/1968Alexander et al 75.5 the corresponding metals, without reduction of atleast one other oxide present. L. DEWAYNE RUTLEDGE, Primary ExaminerReferences Cited 5 TERRY R. FRYE, Asslstant Exarnlner UNITED STATESPATENTS US. Cl. X.R.

2,972,529 2/1961 Alexander et a1 75.5 75211 3,085,876 4/1963 Alexanderet al 75.5

